Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
  • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
  • A61K9/5005—Wall or coating material
  • A61K9/5021—Organic macromolecular compounds
  • A61K9/5036—Polysaccharides, e.g. gums, alginate; Cyclodextrin
  • A61K9/5042—Cellulose; Cellulose derivatives, e.g. phthalate or acetate succinate esters of hydroxypropyl methylcellulose
  • A61K9/5047—Cellulose ethers containing no ester groups, e.g. hydroxypropyl methylcellulose
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/33—Heterocyclic compounds
  • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
  • A61K31/435—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with one nitrogen as the only ring hetero atom
  • A61K31/44—Non condensed pyridines; Hydrogenated derivatives thereof
  • A61K31/4402—Non condensed pyridines; Hydrogenated derivatives thereof only substituted in position 2, e.g. pheniramine, bisacodyl
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
  • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
  • A61K9/5089—Processes

Definitions

• the present invention relates to a procedure for encapsulating chlorpheniramine, in particular to a process for the preparation of individual taste masked microcapsules containing a predetermined amount of chlorpheniramine maleate. More particularly the present invention is directed to a process for the preparation of individual taste masked microcapsules containing a predetermined amount of chlorpheniramine maleate by microencapsulating the chlorpheniramine maleate in a heated coacervation medium including cyclohexane, an encapsulating polymer and a phase inducing polymer and subsequently cooling the coacervation medium. In the process of the present invention, an excess of chlorpheniramine maleate above the predetermined amount is charged to the coacervation medium in an amount sufficient to saturate the cyclohexane in the coacervation medium.
• a method is provided wherein a core material such as chlorpheniramine maleate, which is somewhat soluble in cyclohexane, can be encapsulated in a predetermined amount with respect to the coating polymer and/or in a predetermined amount with respect to a different pharmaceutical, such as pseudoephedrine hydrochloride, in admixture with the chlorpheniramine maleate, in order to maintain a definite ratio of chlorpheniramine maleate to pseudoephedrine hydrochloride.
• a core material such as chlorpheniramine maleate, which is somewhat soluble in cyclohexane
• the encapsulation of the predetermined amount of chlorpheniramine maleate is accomplished by first charging to the coacervation medium an excess of chlorpheniramine maleate above the predetermined amount sufficient to saturate the cyclohexane and/or the coacervation medium with chlorpheniramine maleate. After settling of the microcapsules the coacervation medium is decanted and/or filtered and the microcapsules may optionally be washed with additional cyclohexane. The remaining cyclohexane saturated with chlorpheniramine maleate can be recycled for use in processing the next batch. Alternatively, the dissolved chlorpheniramine maleate can be separated from the cyclohexane and recovered.
• the preferred coacervation medium includes cyclohexane alone or in admixture with hexane.
• Cyclohexane when saturated with chlorpheniramine maleate at 80°C contains 148.8 micrograms of chlorpheniramine maleate per milliliter of cyclohexane. Analytical testing has shown that there is no degradation of chlorpheniramine maleate in the cyclohexane so that recycling of the saturated cyclohexane is possible.
• the chlorpheniramine maleate saturation of the cyclohexane is accomplished before the encapsulation process begins.
• the chlorpheniramine maleate to be encapsulated can be added to the pretreated cyclohexane alone or in conjunction with another pharmaceutical material, such as pseudoephedrine hydrochloride, with which it is commonly administered in a combined dosage form.
• a mixture of the chlorpheniramine maleate and the other pharmaceutical material are granulated to form a drug combination having defined proportions of each ingredient for a suitable dosage form.
• the proportions can be 7.5 milligrams of pseudoephedrine hydrochloride and 0.5 milligrams of chlorpheniramine maleate. Accordingly the drug ratio in the granular material and in the encapsulated granules would be 7.5 to 0.5.
• the ethylcellulose suitable for use as the encapsulating polymer can be any of the commercial types customarily used for encapsulating purposes.
• a typical ethylcellulose has a 45 to 50 per cent ethoxyl content and a 95 - 110 cps viscosity.
• the amount of ethylcellulose employed can vary but for taste masking purposes, the ethylcellulose should comprise about 25% to 35% by weight of the coated granules.
• the ethylcellulose used in the following examples was Ethylcellulose, NF manufactured by Dow Chemical Company having a 49.4 per cent ethoxyl content and a 103.6 cps viscosity.
• the polyethylene suitable for use as the phase inducer can have a molecular weight of between 5,000 and 10,000 and can be any of the commercial types customarily used for encapsulating purposes.
• the amount of polyethylene employed depends somewhat on the type employed but the amount should usually provide a ratio to the ethylcellulose of about 4:1 to about 8:1 parts by weight of ethylcellulose per part by weight of polyethylene.
• the brand of polyethylene used in the following examples was Epolene C-10, manufactured by Eastman Kodak Company, viscosity at 150°C of 8175 cps within the range of 7000 - 11000 cps and a softening point of 101.6°C within the range of 95 - 110°C.
• This example illustrates the use of the process of the invention to provide taste masked encapsulated granules of chlorpheniramine maleate and pseudoephedrine hydrochloride for incorporation into children's tablets.
• the granules containing the raw drug were prepared by first preparing a mixture containing 33.4 - 36.9% by weight of pseudoephedrine hydrochloride, 2.23 - 2.46% by weight of chlorpheniramine maleate and the remainder being microcrystalline cellulose. Because of the required low combination dosage level of the drugs the inert carrier was used to achieve acceptable dose level uniformity. The granulation was accomplished in this instance in a top spray fluid bed unit. The granules had a typical particle size range as shown below. US Std.
• the granules may be prepared by other granulation techniques known to the art such as wet granulation. See for example US. Patent Nos. 5,084,278 and 3,872,227.
• Example 2 the ingredient amount and operating conditions were the same as in Example 1 except that the granule content was 60 grams and the ethylcellulose content was 20 grams providing a phase ratio of 3:1 but an ethylcellulose concentration of 2%.
• the sieve analysis is shown in the third column of the table below.
• Example 1 had an acceptable taste masking of the bitter taste of the pharmaceutical ingredients and had a good mouth feel.
• the product was of an appropriate particle size and met an acceptable release for in vitro requirements.
• Process variables for the pseudoephedrine hydrochloride -chlorpheniramine maleate combination for taste masking purposes are a phase ratio of 2:1 through 4:1 parts by weight of granules per part by weight of ethylcellulose, a 2% through 4% concentration of ethylcellulose in cyclohexane, and a 0.4 through 0.65% concentration of polyethylene in cyclohexane.
• Operation variables include sufficient agitation to keep the microcapsules suspended in the coacervation medium during and after their formation and a temperature range including a maximum temperature of about 80°C and a minimum temperature of about 30 - 35°C.
• Chlorpheniramine maleate should be heated with the cyclohexane as a first step to saturate the cyclohexane and the other ingredients can be added following standard microencapsulating procedure at a temperature sufficiently high to dissolve the ethylcellulose and the polyethylene.
• Optimum values for the process variables are a phase ratio of 3:1, a 3% concentration of ethylcellulose in cyclohexane, a 0.5% concentration of polyethylene in cyclohexane, and a total solids concentration of 12.5% in cyclohexane to provide 25% by weight ethylcellulose coated granules.

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• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Pharmacology & Pharmacy (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Engineering & Computer Science (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Medicinal Preparation (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (1)

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• 1995
  • 1995-02-03 US US08/383,033 patent/US5622723A/en not_active Expired - Lifetime
• 1996
  • 1996-01-29 CA CA002168330A patent/CA2168330A1/en not_active Abandoned
  • 1996-01-31 CO CO96004106A patent/CO4700419A1/es unknown
  • 1996-02-01 AR ARP960101252A patent/AR004473A1/es unknown
  • 1996-02-01 EP EP96300729A patent/EP0724880A1/en not_active Withdrawn
  • 1996-02-02 BR BR9600310A patent/BR9600310A/pt active Search and Examination

Patent Citations (2)

Non-Patent Citations (1)

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